msm: vidc: Allow 0 filled length qbuf

Allow client to send 0 filled length qbuf,
to avoid v4l2 core from setting filled length
to alloc length.

Change-Id: I6c320cc31048584f2f57badaba94776e0cdd73d9
Signed-off-by: Surajit Podder <spodder@codeaurora.org>
diff --git a/drivers/media/platform/msm/vidc_3x/msm_vidc.c b/drivers/media/platform/msm/vidc_3x/msm_vidc.c
index dd966f3..16db81c 100644
--- a/drivers/media/platform/msm/vidc_3x/msm_vidc.c
+++ b/drivers/media/platform/msm/vidc_3x/msm_vidc.c
@@ -1075,6 +1075,7 @@
 		q->ops = msm_venc_get_vb2q_ops();
 	q->mem_ops = &msm_vidc_vb2_mem_ops;
 	q->drv_priv = inst;
+	q->allow_zero_bytesused = 1;
 	return vb2_queue_init(q);
 }